Battle of Mars-la-Tour
1870 CE.
Shown on the map at 49.103°, 5.872°.
The Battle of Mars-la-Tour (also known as the Battle of Vionville or Battle of Rezonville) was fought on 16 August 1870, during the Franco-Prussian War, near the village of Mars-la-Tour in northeast France. One Prussian corps, reinforced by two more later in the day, encountered the entire French Army of the Rhine in a meeting engagement and, following the course of battle, the Army of the Rhine retreated toward the fortress of Metz.
Text from the Wikipedia article Battle of Mars-la-Tour, licensed CC BY-SA 4.0.